The GenNext submssion entitled ?Tailoring the Hydroxy Radical Foot-Printing Approach to Provide a Solution for the Higher Order Structural Analysis Needs of the Biopharmaceutical Industry? is responsive to the ackowledged need for new and improved tools for higher order structural analysis (HOS) of biopharmaceuticals. Unlike conventional drugs, biopharmaceuticals are complex, heterogeneous mixtures of 3- dimensional biomolecules, whose safety and efficacy is reliant upon proper HOS. The presence of proteins with improper higher order structure (HOS) has been linked to severe adverse drug reactions (ADR), alerting the biopharmaceutical industry to the critical role of HOS, while establishing the need for new and improved HOS analytics. An emerging HOS analysis technique is hydroxyl radical foot-printing (HRPF). HRPF involves the irreversible labeling of a protein's exterior by reaction with hydroxyl radicals with subsequent MS analysis to identify the outer portions of the protein. The most widely used method for generating OH radicals employs a quick burst of UV light, and is appropriately called fast photochemical oxidation of proteins (FPOP). Typically, a powerful and expensive UV laser is used. Academic laboratories have demonstrated the utility of FPOP for HOS analysis; however adoption in pharma has been minuscule at best. We have identified barriers that have limited the adoption of the HRPF approach in the biopharmaceutical industry. These impediments include: 1) The use of expensive lasers that demand substantial safety precautions; and 2) the irreproducibility of FPOP caused by background scavenging of OH radicals that complicate and limit comparative studies. As such, there are no commercial sample preparation devices for FPOP analysis, despite the demonstrated need for the HOS analytical power. The GenNext proposal creates an improved means of performing HRPF analysis by replacing expensive, hazardous lasers with a flash oxidation system. Moreover, a custom internal standard (actinometry) system will be included to facilitate ease of use and improve reproducibility. These innovative advancements will decrease the barrier to adoption of HRPF for HOS analysis and will result in accelerated adoption with concomitant impact on biopharmaceutical research and development.